Plan is to head south on JMT from Onion Valley, summit Whitney ( maybe sleep on summit) then head back north to Lake South America, over the KK divide to lake Reflection, west via Bubbs to Roads End for a resupply and then north for section 1 of the SHR to Palissade Lakes, then finish the loop heading south on the JMT back to Onion Valley TH.

Many insulation items still being debated. I tend to sleep cold below freezing. My last trip to Yosemite a month ago I was freezing so I want to lean towards warmer this time around given that we'll be there the second half of Sept. Having a hard time deciding between the two quilts amongst other things.

OR Helium II. Thinking of leaving Houdini behind, seems redundant given what I'll be carrying, but still undecided. I know it's a long standing debate here and I don't have much to contribute to it. I've done Sierra trips with and without and been happy both ways.

The windshirt debate is a debate that cannot be won or lost. I have used several wind shirts over the years with mixed results and was never a real "convert." Since buying the Houdini, it has become the one clothing item I bring on every trip. I even bought one to carry in my computer bag. Great on airplanes too.

I missed the Helium.

Overall the gear list looks great.

What is the asterisk next to the Trailstar for? I wouldn't need a bivy with that shelter and a 20F quilt, along with the other insulation.

I like my houdini as well. I agree it's a no win argument, but I think I'll be Ok without it this trip. I may feel differently afterwards.

asterix indicate items (and weight) which are shared between me and buddy. We plan on sleeping out as much as possible but we'll have the trailstar in case we get rain or snow. I like the bivy in that situation, especially with a quilt but I see your point.

I have a couple routes in mind but we'll evaluate depending on time of day and weather. Harrisson is the obvious choice, but I've read of an easier option going north located between Lucy's foot and Milly's foot that drops you directly at Lake Reflection. Both of those are also on the list. It promises to be the crux of the first half of our trip. Looking forward to solving that little puzzle.

When you are scrambling around those rocky cliffs, you probably don't want to do anything that drops you directly anyplace.

I would think that you could walk down Harrison Pass without much trouble as long as you are wearing some moderately serious gaiters. That is one big loose rock pile.

There used to be a regular trail that went through Harrison Pass, but it was abandoned a long time ago. NPS probably could not keep it clear of snow in the early season and then rock in the late season. You can still see a few tiny traces of it near the top of Harrison Pass.

I did notice and research that old trail appearing and dissapearing on various vintages of topos.That's what initially drew my attention to the area when looking for an alternate route back north from Whitney.

I'd bring the warmer clothing and quilt. It can get really cold in late September. I did the Rae Lakes loop during the last weekend of September a few years ago and down at 8,000 ft the daytime high one day was 34F. I would expect overnight lows in the mid 20's by the end of your trip, with a small chance of them dropping into the teens.

Also, you'll be really glad you packed a rain shell if you get hit with an early season wet snowstorm.

I would err on the warm side on everything. Weather at the end of September is extremely variable. You can fry or freeze. And I'd be prepared to deal with significant snow if it happens – and it can. I've been out at the end of September after a sizable snowstorm and got snowed on driving back from that trip. That means both gear-wise and and having a route or routes in mind if you need to bail. Some of that XC terrain, especially any talus, can be pretty heinous with 6" of snow on it.

Should be a great trip. Most Septembers are mostly mighty nice, and you'll have it almost all to yourselves.

My last extended trip in the Sierras was southbound on the JMT in 2009 and was 10 days later in the year going from Yosemite to Palisade Lakes. I saw the weather morph with the elevation and the calendar. We ended up bailing back north and east over Bishop pass in a long day due to an incoming storm that ended up dumping a lot of snow at higher elevation on Oct 3rd and 4th. I have no doubt we would of been OK higher up but I would of had very cold feet in my already destroyed Salomon shoes and we would not of been able to finish in the amount of time we had. Hence this year I'm going 10 days earlier and planning a few extra days to allow for some shelter time.

Some of my clothing options (BPL Merino hoodie and MB Thermawrap) kept me plenty warm on that trip and provided some nice wetter weather insurance vs. an all down insulation approach. Part of the calculations I'll be making as I study the long range forecasts as the week progresses.

I have bail options and alternate routes all figured out and we are taking a smaller scale paper map covering most of SEKI to have all option mapped out depending on where in the trip we find ourselves. I'm also counting on getting a weather report at the Road's end ranger station as we embark on the second half of the trip onto the SHR. If it looks like bad weather we'll abort and route out using trails rather than the high route.

Some pictures from the morning of Oct 3 2009 which convinced me the weather was changing for the worse and that we needed to bail:

Evening of Oct. 3rd, 2009 from Lake Sabrina trailhead. Clouds like this in October usually only mean one thing:

Love the pics. Those are some gnarly clouds. Sounds like you know what you're getting in to. I'm sure you will have a great time – that is truly an all-star tour of SEKI. This is my favorite time of year to go backpacking. A pair of grocery bags as VBL socks weighs almost nothing and will keep your feet much, much warmer if you do end up having to hike out in fresh snow.

P.S. How do you like the cuben Trailstar? I have the silnylon one and I'm considering switching, but most of the reviews online say it's hard to get a taut pitch.